注射成形钕铁硼粘结磁体研究的现状及前景

论述了注射成形钕铁硼粘结磁体的特点及发展趋势,分析了其生产工艺中的4个关键因素,包括磁粉、粘结剂与藕联剂、注射过程、充磁过程,并对这4个关键因素的研究状况作了综合评述,认为今后注射成形钕铁硼粘结磁体的研究开发将主要集中在以下4个方面研究:各向异性粉末和各向异性粘结磁体,研发合适的粘结体系及注射成形工艺参数,开发磁能积更高的磁体,开发耐热钕铁硼粘结磁体。     

粘结钕铁硼磁环在高性能永磁式步进电动机上的应用

钕铁硼粘结磁体是一种将钕铁硼磁粉与高分子树脂或塑料或低熔点合金及各种添加剂均匀混合,用模压、挤出或注射成形等方法制成的复合永磁材料。国内外对其机理的研究已比较深入,本课题仅就钕铁硼粘结磁体特别是应用于高性能永磁式步进电动机的粘结钕铁硼多极磁环的制备工艺中的关键问题进行了研究,内容包括：（１）专用粘结剂的选择;（２）磁粉选择;（３）薄壁磁环自动压制成形;（４）表面防锈处理方式的选择;（５）多极充磁;（６）磁环转子整体注射成形。结果表明：在解决了上述关键工艺问题后,粘结钕铁硼多极磁环已批量应用于高性能永磁式步进电动机,替代进口或使原有的电机升级换代     

注射成形钕铁硼粘结磁体研究的现状及前景

论述了注射成形钕铁硼粘结磁体的特点及发展趋势，分析了其生产工艺中的四个关键因素。包括磁粉，粘结剂与耦联剂，注射过程，充磁过程，并对这四个关键因素的研究状况作了综合评述，认为今后对注射成形钕铁硼粘结磁体的研究开发将集中在四个主要的方面。     

注射成形粘结钕铁硼磁体制造工艺

磁体的注射成形是一种高效生产的近净成形技术。本文说明了注射成形粘结钕铁硼磁体用复合粉和磁体的制造工艺及性能测试方法。研究了粘结剂、添加剂的含量以及磁粉装载量对注射成形磁体的加工性能、磁性能及力学性能等的影响规律。并从微观上揭示了其机理。用MQP-B快淬钕铁硼磁粉和尼龙12粘结剂制备出了磁性能为Br:0.539 T,Hcb:345.37 k A/m,Hci:681.02 k A/m,(BH)max:47.37 k J/m3的注射成形钕铁硼磁体。     

粘结钕铁硼永磁体的发展浅议

介绍了粘结钕铁硼永磁体的磁粉制备，及磁体生产的不同方法，以及它们的应用方面，并对国外的研究及生产情况了分析比较，还就我国发展粘结钕硼永磁体提出了看法。     

注射成形粘结钕铁硼磁体复合粉研究

磁体的注射成形是一种高效生产的近净成形技术。为了制备出具有较好综合性能的注射成形粘结钕铁硼永磁材料,研究了粘结剂对注射成形磁体的磁性能、加工性能及力学性能的影响;分析了硅烷系列的偶联剂、复合润滑剂和抗氧剂等添加剂对注射成形磁体性能的影响。结果表明,用MQP-B快淬钕铁硼磁粉和尼龙12粘结剂制备出了剩余磁感应强度为0.539 T,磁感矫顽力为345.37 k A/m,内禀矫顽力为681.02 k A/m,最大磁能积为47.37 k J/m3的注射成形钕铁硼磁体。     

磁粉及其偶联处理对压延取向橡胶粘结磁体性能的影响

通过对压延取向橡胶粘结磁体的磁性能及力学性能的测量和在扫描电镜上对磁粉颗粒形貌及粘结磁体拉伸断口形貌的观察研究，表明同样条件下，磁粉径厚比分布合理是保证粘结磁体性能的关键。磁粉大小均匀，径厚比大约在3．0～4．0之间时，磁体综合性能良好；偶联剂的种类及偶联处理工艺也对磁体性能有重要影响。     

注射成型粘结NdFeB永磁体

介绍了粘结永磁体的制备工艺,快淬NdFeB磁粉,HDDR磁粉及粘结磁体的磁性.提出了目前注射制备NdFeB磁体的技术开发要点.     

模压成形各向异性NdFeB粘结磁体性能研究

采用模压成形方法制备各向异性粘结NdFeB磁体,主要研究了粉末粒度以及取向磁场强度对粘结磁体磁性能和力学性能的影响.试验结果表明,随着磁粉粒度的减小,粘结磁体的剩磁有所增加,但矫顽力下降明显.随着取向磁场强度的增大,粘结磁体剩磁进一步提高,各向异性明显;粘结磁体密度及抗压强度随磁粉粒度的减小略有提高.经粒度配比后制备的粘结磁体获得了较高的磁性能和抗压强度,其B_r、H_(ci)及σ_(bc)分别为0.81T、828kA/m及204MPa.     

北科大近终形粘结磁体研究项目顺利通过验收

3月 2 6日 ,北京市科技计划项目“近终形粘结磁体的研究及各向异性NdFeB磁粉中试”顺利通过验收 ,该项目由北京科技大学曲选辉教授领导的课题组承担的。其中 ,各向异性NdFeB磁粉、磁体的性能指标全部超出合同要求 ,自主开发的径轴向两用磁场注射成形机达国际先进水平 ,并获北京市科学技术二等奖。该项目的目标是建立一条年产 30t的各向异性NdFeB磁粉中试生产线 ,解决粘结磁体精密成形关键技术及设备问题 ,推广近终形粘结磁体的应用领域北科大近终形粘结磁体研究项目顺利通过验收     

HDD法粘结NdFeB磁体的磁性能

研究了NdFeB合金成分、均匀化处理和HDD处理脱氢过程对磁性粉末及粘结磁体磁性能的影响。实验表明,HDD法制备的NdFeB粉末具有较好的温度稳定性和时间稳定性。     

添加Zr对NdFeB合金HDDR磁粉的磁性能及显微组织的影响

本文主要研究了合金元素 Zr对 Nd Fe B合金 HDDR磁粉的磁各向异性和显微组织结构的影响。研究结果表明 ,Nd Fe Zr B合金磁粉出现了磁各向异性 ,且其显微组织中出现了针状的富 Zr相。     

Magnetic Properties and Intergranular Action in Bonded Hybrid Magnets

Magnetic properties and intergranular action in bonded hybrid magnets,based on NdFeB and strontium ferrite powders were investigated.The long-range magnetostatic interaction and short-range exchange coupling interaction existed simultaneously in bonded hybrid magnets,and neither of them could be neglected.Some magnetic property parameters of hybrid magnets could be approximately obtained by adding the hysteresis loops of two magnets pro rata.     

Influence of Heat Treatment on Microstructures and Properties of Nd8Fe78B6Co4 Alloy

Melt-spun Nd8Fe78B6Co4 magnetic powders and their bonded magnets were prepared with the optimization of compositions and preparation techniques. The microstructure change of alloy NdFeB and the relation between microstructure and heat-treatment were studied. The heat-treatment temperature is 200～700 ℃. The as-cast structure of the alloy is typically amorphous. Different melt-spun speed and different heat treatment could result in different magnetic properties of NdFeB magnets. Magnetic properties of NdFeB increase with the addition of element Co. The magnetic properties of magnet alloy get the best when the melt-spun speed reaches 23～26 m·s-1, heat treatment temperature is 690 ℃ and time is 30 min.     

Magnetic properties and magnetization mechanism of anisotropic NdFeB/SmFeN hybrid bonded magnets prepared with different coercivity NdFeB powders

Anisotropic NdFeB/SmFeN hybrid bonded magnets were prepared by warm compaction process under an orientation magnetic field of 22 kOe,mixing with anisotropic SmFeN powders in different addition and HDDR-NdFeB powders in different coercivity.With the addition of 20 wt% SmFeN,the density and remanence of hybrid magnets increase from 5.58 g/cm³,8.4 kGs to 6.02 g/cm³,9.0 kGs,respectively.And as the addition amount of SmFeN powders varies from 20 wt% to 40 wt%,the maximum energy ...     

Manufacturing of Injection-Molded NdFeB Magnet with (BH)max111 kJ · m-3

The bonded NdFeB magnets prepared by injection molding meet with the development tendency of the magnet in small volume, light weight and high performance ,and have a good prospect.In this paper, a modified nylonbased binder was developed for powder injection molding of NdFeB bonded magnets.The effects of pretreatment of NdFeB anisotropic magnetic powder produced with HDDR processing on the anti-oxidation behaviors of powder and the final magnetic properties of the molded bonded magnets were studied.The optimal powder loading of 65 vol% was achieved with the modified binder.It was found that the properties of the bonded magnets were mainly affected by the powder surface pretreatment and the intensity of the applied alignment magnetic field during injection molding for a certain powder.Bonded magnets with remanence of 0.820 T, intrinsic coercivity of 1140.3 kA· m-1 and maximum energy product of 111 kJ · m-3 were produced with the optimal processing.     

HDDR NdFeB磁粉两步法伴温磁场取向制备高性能柔性各向异性NdFeB黏结磁体

利用高性能吸氢-歧化-脱氢-再复合(HDDR)NdFeB各向异性磁粉,通过两步法伴温磁场取向工艺制备高性能柔性各向异性NdFeB黏结磁体,重点研究了两步法伴温磁场取向工艺制备出不同成分配比磁体的磁性能和力学性能.结果发现:制备出磁体的取向度有大幅度提高,当成分配比(质量分数)为96.5%磁粉+1%偶联剂+2.5%黏结体系的磁体在120℃加热保温30 min磁场取向后,磁能积达到97 kJ·m-3,而磁体的矫顽力最大降幅只有1.3%,论证了两步法伴温磁场取向工艺制备柔性各向异性NdFeB黏结磁体在实际生产的可行性.环氧树脂润滑剂的加入使得制备出磁体的延伸率和柔性均大幅度下降,并且加入量越多,下降幅度越大,因此环氧树脂润滑剂最大加入量不应超过1%(质量分数).